// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/android/library_loader/library_prefetcher.h"

#include "base/debug/proc_maps_linux.h"
#include "base/memory/shared_memory.h"
#include "testing/gtest/include/gtest/gtest.h"
#include <stddef.h>
#include <stdint.h>
#include <string>
#include <sys/mman.h>
#include <vector>

namespace base {
namespace android {

    namespace {
        const uint8_t kRead = base::debug::MappedMemoryRegion::READ;
        const uint8_t kReadPrivate = base::debug::MappedMemoryRegion::READ | base::debug::MappedMemoryRegion::PRIVATE;
        const uint8_t kExecutePrivate = base::debug::MappedMemoryRegion::EXECUTE | base::debug::MappedMemoryRegion::PRIVATE;
        const size_t kPageSize = 4096;
    } // namespace

    TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchNoRange)
    {
        const base::debug::MappedMemoryRegion regions[4] = {
            base::debug::MappedMemoryRegion { 0x4000, 0x5000, 10, kReadPrivate, "" },
            base::debug::MappedMemoryRegion { 0x4000, 0x5000, 10, kReadPrivate, "foo" },
            base::debug::MappedMemoryRegion {
                0x4000, 0x5000, 10, kReadPrivate, "foobar.apk" },
            base::debug::MappedMemoryRegion {
                0x4000, 0x5000, 10, kReadPrivate, "libchromium.so" }
        };
        for (int i = 0; i < 4; ++i) {
            ASSERT_FALSE(NativeLibraryPrefetcher::IsGoodToPrefetch(regions[i]));
        }
    }

    TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchUnreadableRange)
    {
        const base::debug::MappedMemoryRegion region = {
            0x4000, 0x5000, 10, kExecutePrivate, "base.apk"
        };
        ASSERT_FALSE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
    }

    TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchSkipSharedRange)
    {
        const base::debug::MappedMemoryRegion region = {
            0x4000, 0x5000, 10, kRead, "base.apk"
        };
        ASSERT_FALSE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
    }

    TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchLibchromeRange)
    {
        const base::debug::MappedMemoryRegion region = {
            0x4000, 0x5000, 10, kReadPrivate, "libchrome.so"
        };
        ASSERT_TRUE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
    }

    TEST(NativeLibraryPrefetcherTest, TestIsGoodToPrefetchBaseApkRange)
    {
        const base::debug::MappedMemoryRegion region = {
            0x4000, 0x5000, 10, kReadPrivate, "base.apk"
        };
        ASSERT_TRUE(NativeLibraryPrefetcher::IsGoodToPrefetch(region));
    }

    TEST(NativeLibraryPrefetcherTest,
        TestFilterLibchromeRangesOnlyIfPossibleNoLibchrome)
    {
        std::vector<base::debug::MappedMemoryRegion> regions;
        regions.push_back(
            base::debug::MappedMemoryRegion { 0x1, 0x2, 0, kReadPrivate, "base.apk" });
        regions.push_back(
            base::debug::MappedMemoryRegion { 0x3, 0x4, 0, kReadPrivate, "base.apk" });
        std::vector<NativeLibraryPrefetcher::AddressRange> ranges;
        NativeLibraryPrefetcher::FilterLibchromeRangesOnlyIfPossible(regions,
            &ranges);
        EXPECT_EQ(ranges.size(), 2U);
        EXPECT_EQ(ranges[0].first, 0x1U);
        EXPECT_EQ(ranges[0].second, 0x2U);
        EXPECT_EQ(ranges[1].first, 0x3U);
        EXPECT_EQ(ranges[1].second, 0x4U);
    }

    TEST(NativeLibraryPrefetcherTest,
        TestFilterLibchromeRangesOnlyIfPossibleHasLibchrome)
    {
        std::vector<base::debug::MappedMemoryRegion> regions;
        regions.push_back(
            base::debug::MappedMemoryRegion { 0x1, 0x2, 0, kReadPrivate, "base.apk" });
        regions.push_back(base::debug::MappedMemoryRegion {
            0x6, 0x7, 0, kReadPrivate, "libchrome.so" });
        regions.push_back(
            base::debug::MappedMemoryRegion { 0x3, 0x4, 0, kReadPrivate, "base.apk" });
        std::vector<NativeLibraryPrefetcher::AddressRange> ranges;
        NativeLibraryPrefetcher::FilterLibchromeRangesOnlyIfPossible(regions,
            &ranges);
        EXPECT_EQ(ranges.size(), 1U);
        EXPECT_EQ(ranges[0].first, 0x6U);
        EXPECT_EQ(ranges[0].second, 0x7U);
    }

    TEST(NativeLibraryPrefetcherTest, DISABLED_TestPercentageOfResidentCode)
    {
        size_t length = 4 * kPageSize;
        base::SharedMemory shared_mem;
        ASSERT_TRUE(shared_mem.CreateAndMapAnonymous(length));
        void* address = shared_mem.memory();

        std::vector<NativeLibraryPrefetcher::AddressRange> ranges = {
            { reinterpret_cast<uintptr_t>(address),
                reinterpret_cast<uintptr_t>(address) + length }
        };

        // Remove everything.
        ASSERT_EQ(0, madvise(address, length, MADV_DONTNEED));
        // TODO(lizeb): If flaky, mock mincore().
        EXPECT_EQ(0, NativeLibraryPrefetcher::PercentageOfResidentCode(ranges));

        // Get everything back.
        ASSERT_EQ(0, mlock(address, length));
        EXPECT_EQ(100, NativeLibraryPrefetcher::PercentageOfResidentCode(ranges));
        munlock(address, length);
    }

    TEST(NativeLibraryPrefetcherTest,
        DISABLED_TestPercentageOfResidentCodeTwoRegions)
    {
        size_t length = 4 * kPageSize;
        base::SharedMemory shared_mem;
        ASSERT_TRUE(shared_mem.CreateAndMapAnonymous(length));
        void* address = shared_mem.memory();

        size_t length2 = 8 * kPageSize;
        base::SharedMemory shared_mem2;
        ASSERT_TRUE(shared_mem2.CreateAndMapAnonymous(length2));
        void* address2 = shared_mem2.memory();

        std::vector<NativeLibraryPrefetcher::AddressRange> ranges = {
            { reinterpret_cast<uintptr_t>(address),
                reinterpret_cast<uintptr_t>(address) + length },
            { reinterpret_cast<uintptr_t>(address2),
                reinterpret_cast<uintptr_t>(address2) + length2 }
        };

        // Remove everything.
        ASSERT_EQ(0, madvise(address, length, MADV_DONTNEED));
        ASSERT_EQ(0, madvise(address2, length, MADV_DONTNEED));
        // TODO(lizeb): If flaky, mock mincore().
        EXPECT_EQ(0, NativeLibraryPrefetcher::PercentageOfResidentCode(ranges));

        // Get back the first range.
        ASSERT_EQ(0, mlock(address, length));
        EXPECT_EQ(33, NativeLibraryPrefetcher::PercentageOfResidentCode(ranges));
        // The second one.
        ASSERT_EQ(0, mlock(address2, length2));
        EXPECT_EQ(100, NativeLibraryPrefetcher::PercentageOfResidentCode(ranges));
        munlock(address, length);
        munlock(address2, length);
    }

} // namespace android
} // namespace base
